1. Field of the Invention
The invention generally relates to power units and more particularly to an improved power unit adapted to respond to radial expansion of a helical spring for imparting rotary motion to an output shaft provided therefor.
The advent of increased concern for environmental pollution and the coexisting concern for decreasing supplies of petroleum has caused a great deal of interest to be focused on the development of power units which can be utilized to replace petroleum fueled internal combustion engines. Unfortunately, to date, little progress has been made in developing engines which do not rely upon petroleum fuels. For example, exhaustive efforts in the further development of electrical power units for propelling automobiles and the like have, generally speaking, met with less than satisfactory results. As can be appreciated by those familiar with the development of such power units, potential energy is stored in electrical storage batteries capable of providing a d.c. output. Unfortunately, such batteries lack adequate storage capacity for storing quantities of energy sufficient for propelling a vehicle over relatively long distances, at relatively high speeds, due to the fact that the storage capacity of batteries of a weight suitable for use in vehicles is simply inadequate.
The use of power units which capitalize upon the generation of steam also have failed to satisfy existing needs as have nuclear power units.
2. Description of the Prior Art
The prior art is, of course, replete with spring-operated power units for use with very small vehicles of the type classed as toys and found in toy stores and similar commercial installations. Among some of the advantages which may be realized through a use of such power units is that such units are of a simple design, are of a relatively, generally lightweight construction and do not burn petroleum fuels. However, as can be fully appreciated by those familiar with the design and operation of power units for use in driving vehicles capable of transporting usable loads over relatively long distances such as those capable of transporting personnel and the like, the use of power units which utilize potential energy stored in stressed springs has not been widely accepted. It is believed that one reason for such nonacceptance is that it has not been deemed feasible to achieve adequate control of energy release for such units. Consequently, the use of springs for storing energy is power units having a capacity for use in driving load-transporting vehicles or for use as a stationary power plant has been substantially ignored.
It is, therefore, the general purpose of the instant invention to provide an improved power unit having an increased capacity for utilizing the potential energy of a stressed spring over periods of extended durations.